The primary objective of this investigation is to isolate and characterize the subunits which either are part of the intracytoplasmic membranes or are located on the surface of such membranes. The nitrifying bacteria to be used in these studies include Nitrosococcus oceanus, Nitrosomonas marina, Nitrobacter winogradskyi, and Nitrococcus mobilis. New techniques will be developed to dissociate the membranes into their respective subunits. The structure and function of the subunits from the intracytoplasmic membranes of these four species will be compared. The subunit structure and its spatial arrangement in the outer membrane of Nitrosococcus oceanus will be described. Emphasis will be placed on the relationship of the peptidoglycan, lipid, lipopolysaccharide and glycoprotein components to each other.